Applied Mechanics and Materials Vol. 742

Abstract: We propose a refractive sensor based on directional coupling between two metal-insulator-metal (MIM) waveguides to measure the refractive index change of the insulator, which is designed to be with a structure of metal-insulator-metal-insulator-metal (MIMIM) in which surface plasmon waves (SPW) are excited. The propagation properties are analyzed by coupled mode theory, and the expressions about the coupling coefficient, coupling length and sensitivity are derived. The sensing properties based on simulation results are also discussed. Compared with a dielectric waveguide, the total size of our sensor with MIMIM waveguide is about one tenth that with dielectric materials, while the sensitivity is improved ten times larger than the former.

Abstract: Piezoelectric Solid-State Micro-machined Modal Gyroscope is a new kind of gyroscope sensor based on MEMS. According to the characteristics of the gyroscope signal, the after-treatment processing system is designed and implemented, including A/D convertor by AD7656 and data storage by SD card. After applying Kalman filter to the digital signal on DSP, 71.8% decrease of standard variance of initial signal is achieved remarkably, which lays the foundation for the practical application of piezoelectric micro-machined modal gyroscope.

Abstract: This paper presents a new micromachined PCR chip with separable electrodes part and reaction chamber part. The electrodes part, employing Pt film resistor as heaters and sensors, is reusable, and the chamber part is a disposable PDMS-GLASS bonded structure. This PCR chip with reusable electrodes can largely reduce fabrication cost. COMSOL software is used to simulate the temperature distribution of the designed chip and then use infrared thermometer (NEC R300SR) to verify temperature distribution of the fabricated chip. The test results turned out to perfectly fit the simulation of temperature distribution, which provides reliable basis for further PCR amplification experiment.

Abstract: Ball pressure test is the heat resistance test of the electrical products material, whether it meets the requirements of material performance to eliminate security risks. Using reading microscope for ball pressure test measurement and its measurement uncertainty was analyzed in this paper, including measurement uncertainty sources, established mathematical model, uncertainty example and measurement uncertainty result. The measurement uncertainty was analyzed to ensure the accuracy of ball pressure test measurement result.

Abstract: In order to improve the precision of Time-grating with Variable Coupling Coefficient, the electrical traveling wave equation was derived in detail base on the further study of working principle of Time-grating sensor. Combined with the processing and assembling methods of sensor, the uncertainty sources of sensor standing wave, synthesis traveling wave signal and the produce reasons of higher harmonic were analyzed by using uncertainty theory. The produce reasons of higher harmonic were verified with spectral analysis of the original sensor error data, and then the primary and secondary uncertainty sources affected the sensor measurement uncertainty sources were got, which were time and spatial orthogonal error, amplitude error of two roads signal and stator and rotor air gap uneven. The conclusion made in this paper can be used to conduct the structure optimal design, sensor error correction and uncertainty evaluation.

Abstract: A large number of the welding processes were used in the construction of the FDSO, and laser shock processing the critical weld can significantly improve the mechanical properties of the weld. For the current difficult to judge the impact of laser shock processing, quality evaluation apparatus and method for laser shock processing by light deflection were proposed for online quality assessment of laser shock processing the weld.

Abstract: CCM.M-K4 is a key international comparison organized by the Bureau International des Poids et Mesures (BIPM) to verify the measurement ability of 1kg stainless weights. This paper reports the process analysis of mass determination of CCM.M-K4 during the measurement in NIM, China. The gravity correction and air bouncy correction are discussed, and the measuring uncertainties of measurement process are evaluated. Mass difference between the test standards is 0.0015 mg, and average mass of both test standards is 0.013 mg. The standard uncertainty of test weights is 0.013 mg.

Abstract: Owing to the distinct advantages, including non-invasive sensing, high safety and low cost, ultrasonic tomography (UT) method is considered as a promising visualization measurement method, in which acquiring high-precision the time of flight (TOF) is crucial for real applications. In this paper, a TOF measurement system is proposed for the UT measurement. The signal analysis is applied for the threshold method to confirm the TOF measurement. The Data acquisition card and the software of Libview are used for the signals acquirement. Experimental studies are implemented to validate the feasibilities of the proposed TOF measurement system, and the experimental results confirm that the TOF measurement system is successful for the TOF measurement.

Abstract: The electrical clearance and creepage distance are two key parameters for the design of MCCB (molded case circuit breaker, MCCB), which directly influences the electrical safety performance of MCCB. In this paper, the electrical clearance and creepage distance measurement uncertainty were evaluated through the uncertainty sources analysis, the mathematical model establishment and the components uncertainty calculation, to ensure the accuracy of the measurement results.

Abstract: This paper presents a 20 Hz to 200K Hz alternating current (AC) and direct current (DC) analog-to-digital converter (ADC). The strange to minimize the zero crossing noise adopts hysteresis comparison technique. Multi-slope integral technique is also employed to enhance measurement accuracy. Furthermore, an algorism is designed to eliminate measure error. The prototype ADC achieves millivolt precision.